Smoke-burning furnace.



No. 695,089. Patented Mar. 11, I902.

J. E. CAVANAGH. SMOKE BURNING FURNACE.

(Application filed may 6, 1901.)

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jm. 695,089. Patented Mar. n, 1902.

J. E. CAVANAGH. v SMOKE BURNING FURNACE.

(Application filed may 6, 1901.)

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No. 695,089 Patented Mar. II, N902.

J. E. CAVANAGH. SMOKE BURNING FURNACE.

(Application filed m a. 1901.

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5,, turns JOHN E.

CAVANAGH, OF CLOQUET, MINNESOTA,

SMOKE BURNING FURNACE.

SPEGIFIOATIQN forming part of LettersPatent No. 695,089, dated March 11,1902.

Application filed May 6, 1901. Serial No. 58,838. (No model.)

To (tZZ whom it rrtrty concern.-

Be it known that I, JOHN E. CAVANAGH, a citizen of the United States,residing at Gloquet, in the county of Carlton andState of Minnesota,have invented certain new and useful Improvements in Smoke-BurningFurnaces; and I do hereby declare the following to be a full, clear, andexact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the same.

My invention has for its object to provide an improved steam-boilerfurnace witha view of securing increased efficiency.

To this end my invention consists of the novel devices and combinationsof devices hereinafter described, and defined in the claims.

The invention is illustrated in the accompanying drawings, wherein likenotations refer to like parts throughout-the several views.

In said drawings, Figure 1 is a view showin g the setting in verticalcentral section and the boiler chiefly in side elevation, with someparts broken away. Fig. 2 is a vertical crosssection on the line 00 a"?of Fig. 1. Fig. 3 is a vertical-cross-section on the line 03 00 0f Fig.1; and Fig. a is a vertical cross-section on the same line as Fig. 2,but showing a modification in the construction of the fire-pot wherein ahorizontal grate is employed instead of a grate with inclined sections.

The masonry setting 1 is of suitable form to support the return-flueboiler 2 and afford a rear-end extension or breech-chamber 3. The boiler2 is provided with a front-end extension 4, having the stack 5. At itsrear end the boiler-shell is tapped by a mud-leg 6,1eading to themud-drum 7. From said muddrum 7 circulating-pipes 8 extend first upwardand then lengthwise of the shell to the front-end extension 4 and thenturn inward and tap the shell through the front-end flueplate. Thecirculating connections 8 are in pairs or sets of two each extendingalongeach side of the boiler-shell at unequal heights, as best shown inFigs. 3 aud t. Of these circulating connections 8 three thereof tap theboiler each other.

the shell. This disposition of said circulating-pipes 8 insures a spiralmotion to the wa ter within the boiler-shell under the heat from thefurnace. This disposition of the circulating-pipes for securing theresult above named, together with the resulting peculiar actions andadvantages therefrom, are set forth in my pending application, SerialNo. 55,611, filed April 13, 1901. The sections of the circulating-pipes8 which extend lengthwise of the boiler-shell are disposed near to theshell, but are spaced apart a short distance therefrom.

The fire-pot has for its back the bridge-wall of the setting 1 and isprovided with a front wall of any suitable construction with suitabledoors properly located therein. The important feature of the fire-pot isthe combination, with the grate, of segmental arches 9, converginginward from the side walls of the setting to the lower members of thecirculat= ing-pipes 8 and abutting against the same at their upper end.These arches 9 are composed of refractory material, such as fire-tile,and when applied as above described flamepassages are afforded betweenthe circulatingpipes 8, abutted thereby, and the boiler-shell.

In my preferred construction the grate-bars 10 are set at an angle tothe horizontal plane, inclining downward from the arches 9 to thedead-plate 11 and are mounted for a rock ing motion. The dead-plate 11has a base of metal and a face or body of refractory material, such asfire brick or tiling.

From the side walls of the setting 1 side arches 12 extend to a junctionwith the boilershell at a point above the center of the same. Thesearches 12 are preferably composed of two courses of refractory material(marked a and a and an outside course a of common brick. The insidecourse a is preferably a fire-tiling, and the intermediate course a ispreferably of fire-brick, with these two courses so disposed as to breakjoints with The side arches 12 extend from the front end wall of thesetting to the rear end wall of the same. The arches 9 extend from theback wall of the fire-pot or so-called bridge-wall of the setting to thefront wall of the setting. Hence the arches 9 and 12, together with theside walls of the setting, cooperate to form large fines orflame-chambers 13, extending from the front end of the boilershell tothe rear end or breech-chamber 3.

The arches 9 are shown as tapped by fuelfeed pipes 14, supplied from amechanical stoker 15. The upper ends of the pipes 14 are subject toclosures 16 under the control of a hand-lever 17, as shown in Fig. 1.This a mechanical stoker, however, may or may not be employed, asdesired. The fuel may of course be supplied by hand through doors (notshown) in the front end wall of the firepot.

Having regard to the action, the chief feature for emphasis in this caseis the more thorough combustion of the fuel. By combining with the gratethe arches 9 of refractory material disposed as described I secure asmoke-consuming furnace. The combustion is so nearly perfect that noappreciable amount of carbon passes off with the gases and into theatmosphere through the stack 5. Under the action of the fire on thegrate the arches 9 become heated to incandescence, and the burning gaseson striking the same are successively reflected backward toward thegrate, and under the intense heat produced from the burning fuel and theincandescent arches 9 complete combustion will be secured. Thereflection from the boiler is also back downward onto the grate at anangle thereto, thereby causing redeflection toward the incandescentarches, and hence the cooling effect from the boiler-shell iscounteracted by the repassage of the gases through the burning mass andtheir contact with the incandescent arches. In this Way, as I havedemonstrated in practice, I secure almost perfect combustion. The flamesand superheated gases on passing from the fire-pot completely envelopthe circulating-pipes 8 and the sides of the boiler-shell in theirpassage rearward to the breech-chamber 3, at which point they enter thetubes of the boiler, thence out to the front end extension 4 of thestack 5. This course of travel is of such great length thatsubstantially all the heat is utilized.

With this form of boiler and furnace I have found in practice thatincreased evaporation for any given unit of fuel can be secured.

With the form of grate shown in Fig. 2 the grate-bars would receive arocking motion whenever necessary by suitable devices. (Not shown.) Ifthe grate be horizontal, as shown in Fig. 4, the dead-plate would bedisposed crosswise of the boiler and the sets of gratebars 10 would beapplied lengthwise of the furnace. The grate might be of any suitableconstruction and provided with any suit-able means for cleaning thesame.

What I claim, and desire to secure by Let ters Patent of the UnitedStates, is as follows:

1. The combination with a steam-boiler having water-circulating pipes onthe side of the shell and spaced apart therefrom, of a firepot havingcombined with the grate segmental arches of refractory material disposedparallel to the shell and with their upper ends abutting against saidcirculating-pipes, substantially as and for the purposes set forth.

2. The combination with a return-flue boiler having water-oi rculatingpipes along the sides of the shell and spaced apart therefrom, of asetting for said boiler, constructed to afford a rear-end extension orbreech-chamber, side arches of refractory material connecting the sidewalls of the setting with the boiler-shell, and a fire-pot havingcombined with the grate segmental arches of refractory material disposedparallel to the shell, and abutting the lower members of saidcirculating-pipes, the said side arches and fire-pot arches cooperatingwith each other and the walls of the setting to afford large fiues orflame-chambers, receiving from the fire-pot and communicating with thebreech-chamber,substantially as and for the purposes set forth.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN E. OAVANAGH.

Witnesses:

WALTER L. CASE, M. K. VVHITTEMORE.

